Adjustable pressure hydraulic valve system



A ril 28, 1953 F. G. CIZEK 2,636,509

ADJUSTABLE PRESSURE HYDRAULIC VALVE SYSTEM Filed March 28, 1946 v sSheets-Sheet 1 Hill- 'l/illl/ 71? 98 0 sm 1144 11 35 mmvrox.

April 28, 1953' -'F.,G. CIZEK ADJUSTABLE PRESSURE HYDRAULIC VALVE .,,SYS TEM Filed March 28, 1946 Sheets-Sheet 2 April 28, 1953 F. G. CIZEK2,636,509

ADJUSTABLE PRESSURE HYDRAULIC VALVE XSTEM Filed March 28, 1946 3 Sheets-Sheet 3 d .9 107 10? i 86 f -114 1; 106 M 112 i ml amok;

W wag? Patented Apr. 28, 1953 ADJUSTABLE PRESSURE HYDRAULIC VALVE SYSTEMI Frank G. Cizek, Chicago, Ill., assignor to American Steel Foundries,Chicago, 111., a corporation of New Jersey Application March 28, 1946,Serial No. 657,816

Claims.

This invention relates to hydraulic systems comprising hydraulicpressure control valves and more particularly to systems incorporatingvalves designed to selectively vary the hydraulic pressure.

My invention contemplates an arrangement of a plurality of selectorseach of which may have a number of pressure stations, any one of whichmay be used to conduct pressure to an adjacent selector likewise havinga plurality of pressure stations, thus making it possible, for example,to have eleven pressures developed by two selectors, each of which wouldhave six stations.

A .general object of the invention is to provide a valve by means ofwhich the operator of a hydraulic machine may select any one of severalpredetermined operating pressures according to the immediate demand ofthe work.

Another object of the invention is to design a control system whereinthe various desired operating pressures may be preset by someone otherthan the operator of the machine, whereby an unskilled operator mayoperate the machine in an easily taught sequence without havingknowledge of the pressure requirements or the reasons therefor.

Another object of the invention is to design a system such as abovedescribed wherein a pressure relief valve connected to the main supplyline of the system is operatively connected to a pressure selector valveby means of which the pressure atwhich the relief valve opens may beregulated to anyone of several predetermined values.

A more specific object of the invention is to design a pressure selectorvalve comprising a body with a cylindrical bore and a plurality ofdischarge ports communicating therewith, said bore being adapted for thereception of a 'complementary stem rotatable therewithin and comprisingpassage means for selectively placing the ports in communication withthe inlet port of the device.

The foregoing and other objects and advantage of the invention willbecome apparent from a consideration of the following specification andthe accompanying drawings wherein:

Figure 1 is a flow diagram of a hydraulic circuit incorporating thenovel pressure selector valve, said circuit being operatively connectedto a typical hydraulic motor partially shown in central vertical crosssection;

Figure 2 is an enlarged central vertical sectional view through theconventional pressure relief valve shown in Figure 1, portions of thevalve bein shown in elevation;

Figure 4 is a sectional view, partly in elevation,

of the pressure selector valve taken in the vertical planes indicated bythe lines 44 of Figure'3 Figure 5 is a fragmentary vertical sectionalView of the pressure selector valve taken in the vertical planeindicated by th line 5-5 of Figure 3;

Figures 6 and 7 illustrate the base plate portion of the selector valvebody, Figure 6 being a top plan view of said base portion and Figure '7being a sectional view taken on the line 1-! of Figure 6; and

Figures 8-10, inclusive, illustrate in detail the pressure selectorvalve stem or spindle, Figure 8 being a side elevation thereof, Figure 9being a to plan view thereof, and Figure 10 being a sectional view takenon the line 10-40 of Figure 8.

Describing the invention in detail and referring first to the flowdiagram illustrated in Figure 1, the hydraulic motor, generallydesignated 2, may be of any conventional design and as illustrated is inthe form of a cylinder 4 with a ram 6 reciprocal therewithin, said ramcomprising an enlarged cylindrical portion 8 slidably fitted within thecylinder to define advance and return chambers 10 and [2, respectively.It will be understood that the system is particularly applicable to ahydraulic press wherein granular material is pressed by means of the ram8 into cavitie of varying cross section. When it is desired to produce asubstantially constant density throughout the mass of compressedmaterial in the cavity, the material is often introduced in smallincrements, each increment being pressed with a difierent diameter punchand witha different gross tonnage. 'As the operation proceeds, eachstroke must produce a different tonnage from the preceding stroke andfrom the succeeding stroke. An example of this type of work is thepressing of explosive material into artillery shells.

The hydraulic circuit associated with the motor 2 comprises a pump l4having its suction side connected to a reservoir or tank I6, said pumphaving its discharge side connected to a pipelor line I8 connected tothe inlet side of a conventional operating valve 20, said valve beingactuated bya lever 22. A conventional safety relief valve 24 is providedin the line I8 between the pump l4 and the valve 20 for the purpose ofpermitting the pump 14 to discharge through a line 25 into the return ordischarge line 26 in the event of blockage in the system, as, forexample, jamming of the valve 20.

It will be understood by those skilled in the art that in the neutralposition of the valve 29, the pressure fluid delivered by the pump I lpasses through the line 18 into the valve 233 and outwardly therefromthrough the pipe or line 28 into the beforeementioned discharge 1ine'28;Inthe advance position of-the valve 26; pressure fluid delivered by thepum [4 is conveyed outwardly from the valve 29 through the advance ormain supply line 30 into the advance chamber. [Got the cylinder therebycausing the ram 5 to be moved on the advance stroke thereof. It may benoted that on the advance stroke of the-ram 3,. the hydraulic fluidWithin the chamber lZis forced through the pipe 36 into the valve 28 andoutwardly therefrom into the return, line 25 through the pipe 28. Whenthe ram reaches the end of its advance stroke, the fluid in the advancechamber I0 is conveyed from the cylinder 4 through, a. pipe. 42connected to. the pipe 35 through a one-way checkvalve 4.4.2.

The pressure. in. the, advance chamber I0;- is; regulated; by. a. reliefvalve 32 .in=.the line. 31);. said valve being. adapted to. open-at a.predetermined; pressure to discharge into the before-mentioned:discharge or. return. lineifi. The-pressure. value at which; the reliefvalve: 32;. opens is. selectively. varied, as hereinafter discussed, byone or more: pressure selector valves.3ll-. Ifdesiredg. onevalve- 34maybe. used. andthe inletiport thereof is;.connected by apipe 3.5..tothe relietvalve 32; theouta let. por.t.of the valve 3:3 being connected:by a. pipe 31 to the return line 28 as hereinafter dis. cussed... Wheremorethanone valve 34 de-s sired, one of the-discharge ports of thefirst;valve/ 3o 34 .is connected by. a, pipe. 39 .to.-.the:.inlet;.portf" the other valve 34, theoutlet .port; of: which. is connected by apipe. to the returnlinert; In thisimanner any desired number of-.valvesBil-may: be arrangedin seriesto accommodate. opening. of the relief.valve 32- at.any.desiredznumber of. predetermined pressure values;

In. the return position of theivalvev the. pressure-fluid. delivered bythe pump- I 4. to said valve\ is v conveyed therefrom through pipe or; 5line 36 connected to thebefore-mentioned return= chamber l2ofthecylinder 4, .w-hereupon :the' ram.

6 moveson the return stroke-thereof to -the point illustrated. in thedrawings, the hydraulic fluid; in theichamber: Ill .being forced throughthe-line intovv the -valve 2B and-outwardly throughrthe: pipe-i28 :into=the disc harge=1ine 26': In th-is con nectionit: may. be noted that.when -tharam 6 reachescthe end of its return stroke, the pressure:-fluid inthe return chamber l2 is conveyed from thecylinder t: through anoutlet: pipe 38 0011- nected to the line- 351- through a. one-waycheckvalve;

Referring now to Figure 2, the relief valve- 32 is illustrated incentral vertical section-,said-v-alvei. being of the-balancedpiston typewherein the piston 46 is slidably fitted within a compl'e mentarybore 33inthe valve body 5lhwhich isprovided-with a passage-or chamber. 52normally conveying. thefluid in the=line-3il to and fromthe chamber ID.The piston 461comprises a= por tion= seated as at '54 againstthe-inner-extremity of aport 5'6 communicating with the-discharge line 26,- said piston being normally maintainediin its closed position by aspring 52'; The. pressure m at opposite. sides oi the-pist0n-ifi' isbalanced by" a throttlepassageorport fill' therethrough; said passagecommunicating w-ith an 1 outlet port: 62 connected to the beiore-mentionedpipe 35a The port 62 also communicatess with--aichamber 64 4normally closed by a valve member 66 springpressed to its closedposition by a spring 68 adjustably compressed by a screw '50. When thepressure in the line 39 reaches a predetermined maximum value, the valvemember 66 is urged to itsopen position, thereby'permitting the piston 46tobe urged upwardly by the hydraulic pressure in the line 30 to permitthe pressure therein to pass into the discharge lin 26, the

fluid in the chamber M being drained through a central passage'iZ'through the piston A6, The valve member 66 is preferably adjusted toopen at a predetermined maximum value so that the valve member- 66functions as a safety valve mechanism;

Referring novvz-toFigures 3 to 5, inclusive, one of the pressureselector valves 34 is illustrated in detail, said valve comprising abody, generally designated M. The body T4 comprises a member '16 with a:caplfii secured theretoby. cap. screws 80, 8t? (Figure. 3 andHth-e body:l lpalso. comprises. a, base plate portion: 82 rsecuredztoz the. bottomor: the member. 18 in any convenientnmanner assby'v cap screws (notshown). The member i4 is pres vided; with acylindrical' bore 84:(Eig-ure.:4); re: ceiving a; complementary stem: cr:spindle:li6 sliablyfittedtherewithin.insubstantially fiuidstightr;engagement'therewith, saidstem beingzrotatable bya handle or knob dd'for a purpose-hereinafter: described. The member'lfi is formed withazplu, rality. of: discharge or: relief" ports; 91h connected; to thebore 8d; each of said-.portsxbeingrclosed; by? a valvemember: as:springepressedlton the. closed:. position thereoftbyv a spring 94adjustably com-r pressed against the valve member by; an:v adj uste ing'screw 9.6, saidv screw extendingithrcughf a; conventional packing;gland. assembly" 98 Each'r port is connected bya passagelllllztonarr-annus. lar passage lil2'.(Figures-a and 5) iii-the formiofa groove formedin the top. ofthei memben'lfi; saidipassage 102 beingconnected hyaport lflktm a chamber H36 defined within-:the.bore-84:12pmreduced portionfll'l of. thestemflt:v Therpassage I02is alsoconnected-to132160111118?ipfll'tilzz'ofl'the valve body 74, as best seen inFigures;3i.and'.:5;,. said outlet port, beingconnected to; the line;3:12. as mentionedtabove.

The stemailfi-is providedtwith.aniannulan groove or passage. I 0.8,communicating, at: all-times: with: the, inlet-port llflroftthe valvebodyfllrand come. municatingzwith a vertical groove; H Zladaptedrto: beselectively. registeredwith; theiports; 90:: It: may be noted that bymeans of the annular groovez. I031; the stem: 86:1. is substantiallyinilaterali bale ance inasmuch asgthe1pressureinf;- the-afluid .with.-.-

in the: bore-8t: is substantially; evenly distributed: to the stemBdaroundtheiperimeteiz thereon; It:: will be understood that :a; slight;amountroivhye draulic -fiuid may leak: between, the stem: Bfilande: thesurf ace; of the member: 75.: defining;- t'hegboreu:

84, despite the. factzthat these: partsiare slidab'lyi' fitted in asubstantially fluid-tight engagement;

and this leakage fluid :is conveyed: to :the; annulani passage I02;through; the chamber: H18 and& the: passage: I0 2, the chamber:lfifisbeingw connected;

by a passage lldwthroughethe:stemtoca: recesss I lGj-imthebaseplate-fli; said plate-beingzaproyided'i with aazplurality-rof.-:grooves Ora slots: 5 Ht; ass-best:

seeniin; Figures 6 land: '7, for; the-purposeofzcomveying, any}. leakagefluidito; the; recess. l 1.6:; It may also be noted that theplate8:Z::is..provided:: with a plurality of; openings:lzlktherethrnugha for theireceptioiq. of =asscciated1capu screws..(notx.

shown) securing.:the: plate,=;82 to the..-bodyamema ber 16.

It will be understood that the spring 54 within each port as isadjustably stressed to a predetermined pressure preferably differentfrom that of the springs M within the other ports 99, and the stem 85 isrotatable by the handle 88 to'selectively place the vertical groove H2in communication with the respective ports 98, whereby the inlet port His connected to any one of the discharge ports QB at the selection ofthe operator. Thus the operating pressure at which the piston it of therelief valve 32 is moved to its open position may be regulated to anyone of a plurality of predetermined values by rotating the stem 36 toplace any desired port 98 in communication with the inlet port l in ofthe valve i i.

In operation of the system, pressure from the relief valve 322 isconveyed by the pipe 35 to the bore 841 of the selector valve 14 and thepressure fluid enters the circumferential groove I08 and flows all theway around the stem 3% and into the groove H2. From the groove M2, thepres sure fluid is conveyed to one of the ports $8 wherein the valvmember 32 remains in the closed position thereof as long as the pressureremains below the predetermined value at which the valve member 92 isarranged to open. When the pressure reaches this predetermined value,the valve member 92 is forced into the open position thereof, allowingthe fluid to flow into the annular chamber H32 and thence into theoutlet port l22 which is connected as above noted to the pipe 3?communicating with the discharge or relief line 26.

As a result of th opening of the valve member 92, the pressure in therelief valve 32 is reduced as above described in connection with thesafety valve member 66, whereupon the relief valve piston 4'6 ispermitted to move to the open position thereof to maintain thepredetermined pressure value within the system.

Before initiating another advance stroke of the ram 6, the handle orknob 88 on the stem 86 may, if desired, be turned to some other positionwhich delivers pressure fluid to some other port 88 wherein the valvemember 92 is adjusted to open when the pressure in the system reachesanother predetermined value. In this connection it may be noted that thestem 88 is maintained in each position thereof whereat the groove H2communicates with one of the ports 95] by a detent mechanism, generallydesignated we and comprising an arm I25 carrying a latch pin i233spring-pressed by a spring I38 into one of the shallow recesses I32formed in the top of the cap member 78 of the body hi. The arm E26 maybe secured to the stem 86 in any desired manner, as, for example, by aset screw.

It may be noted that the stem 88 extends through a complementary openingin the cap l8, said opening being sealed by a conventional packing glandassembly E36 maintained against accidental disassembly by a plurality ofcap screws I38.

If desired, the valve member 92 and associated spring 94 may be removedfrom one of the ports 99 and said port may be connected by thebefore-mentioned pipe 39 to the inlet port lid of another pressureselector valve 34, as above de- 6 scribed and shown in Figure 1. m-thismanner', any desired number of valves 34 may be arranged in seriesto provide any desired number J of predetermined pressure levels atwhich the relief valve 32 will open. Thus, when the range of the firstselector valve 34 is exhausted, the last position of the stem 86 may beselected, which sends pressure fluid over to the second selector valve34, which may then operate through its range before delivering thepressur fluid to the next selector valve; l

It is to be understood that I do not wish to be limited by the exactembodiment of the device shown which is merely by way of illustrationand not limitation as various other forms of the device will, of course,be apparent to those skilled in the art without the claims.

I claim:

departing from the scope. of

1. In a system of the class described, a supply line, means forselectively maintaining the pressure in said line at any one of aplurality of predetermined values, said last-mentioned means comprisinga relief valve, a relief line connected to a port in said valve, apiston in said valve comprising means for normally closing said port,fluid passage means through said piston for conveying pressure fluid toopposite sides thereof to balance the hydraulic pressures thereagainst,a control port in said valve at the side of said piston re-.

mote from the first-mentioned port, a plurality of pressure selectorvalves connected in series and each comprising, a plurality ofindependent relief valve means adapted to open at varying pressurevalues, each pressure selector valve having means for selectivelyconnecting the control port to the relief valve means of said pressureselector valve and to the next pressure selector valve in series.

2. In a system of the class described comprising a supply line connectedto an associated source of pressure fluid for conveying pressure fluidtherefrom, and means for selectively maintaining the pressure in saidline at any one of a plurality of predetermined values, saidlastmentioned means comprising a normally closed relief valve havingopening and closing areas acting upon by pressure fluid in said line andby trapped fluid, respectively, said valve having a throttle passageinterconnecting said areas, said valve being adapted to open when thetrapped fluid therein is bled off, a plurality of pressure selectorvalves connected in series and each comprising a plurality ofindependent bleeder valve means for bleeding off the trapped fluid atvarious pressure values, each of said selector valves comprising meansfor selectively connecting the trapped fluid to the bleeder valve meansof said pressure selector valve and to the next pressure selector valvein series.

3. In a system of the class described; the combination of a line adaptedto deliver fluid from an associated source, relief valve meanscomprising a casing having a valve chamber connected to said line andhaving an exhaust port connected to said chamber, a valve member havinga portion slidably fitted in said valve chamber, said portion having anopening area facing the port and acted on by pressure fluid from saidsource, said member being adapted in the closed position thereof toclose said port from communication with said valve chamber, spring meansin said casing for urging said member to the closed position thereof, aplurality of pressure selector valves connected in series and eachcomprising a astral-itszoiaz nde eneentrb ee errval eszadayho p mait reuau r ss seName txeafi tz p essuree a 1- veiy e m a di e 91 1 315:-

line; connected tear-1 associated .sour-ae of press;

sureefiwida' a1re1ief:i-'va1ve1,-cemp.rismg= a: chamber: connected; taisaidiline; said .1 va-1ve having a cas-r ing portion with an exhaustport conneetedsto the chamber and said valve having a Inc-cablepistoniportiomclesing said port, anopeningpr-es.. sure ag'eaa on";saidrpistom portion acted? on by pressurefiuid fromsaid souree; an'stherarearonsaid. rpiston-v portion. opposing saidtopening areal andactedwmbyfluid trapped inzsaid va1ve, a-

throttle.,port through onewoi said portions interconnecting said';areas, said a piston portion 1 being. adapted to open the exhaustrperttwhen said. trappedi fluidiis- .b1ed 5cff%"fr0m saidtvalve; and aplurality: of pressureselector: valves arranged z in.

series, each offsaid iseleetor valves .having a .-p1u-,

rality: of: independent. bleedervalve means ,1 for bleeding off thetrapped fluid from said; rekief valve; and each: oi: said: selectorvalves: having: means or selectively eonnectinglits bleederrvalvermeansrto the-meliefivalveand :for connecting. the 5 relief Waive to thenext. seleetonvaEve-in series;

52 In an-hydraulic-systemeomprising a supply line connecteditoanassociated fluid: pressure source; the combination of a pressureselector systemecompris-ing a, pair of pressure sezecton va1ves-=eachhaving 1 a hollow body with :an inlet pert and a, plurality-of"discharge: ports, theinlet" portsaofisomswazlwbeingcc,rzznected11:0;oneoft-the ischar epertszafxhemtnetsvaivag.theeothemdise, char e. perils; of: 5131 valves; om ris ng.inde p ni ntz reli f: vaive me nsadaptedr tm pen at: diiferent pressizleevalues a selector stemin Bac b d 1. arm; p ssa e; means. aglapt d:to, selec: tively connect the inletyz ortw'there-of with the:-disggagige portstherepf, a, relief ,valve having a casing with a;chamber subjected tothe pressure, inesaidi ne, exhaustm a-id c singC011:- necteite saidvchamber; a ,stemyadapted to close saiehexhaustPOl'ili and having, aupiston-like portion-,slidgbly :fitted: within a;bore of said. casing, prin zmean o sy ldinely ureinessaid stem to, the:chased; position: thereof, throttle: passage ensfihrcueh' idipcr i nrnew nnection;

b tw en nlet p r-t; of: sai ther: nressu ffi:

lectpnvalye and thep rtion efisaid bjoregremoteq frem;sa; ;e2;haustp.@rt;,

CIZEK:

Rjefierenees Cited the file of; this patent" UNITED STATES PATENTS.

Number! Name Date 825,370: Zurbuch- July 10, 1906 L t-19,472 Wesson Mar.2'7, 1923 1,498,477" Nichles- June 17, 1924 1, 5 38,16?" ChappelI May19, 1925 1,755,451 Morrison Apr. 22,- 1930 1,8G5;656 Taylor May '12,1931 1,921,955 Vickers Aug. 8, 1933 2,192,778- St'acy Mar.- 5, 19402,218,818? Harrington Oct. 22, 1940 2,250,389 Miller July 22, 19412,267,177 T-wyma-n 1 Dec. 23, 1941 2,319,199: L'osey Feb; 2, 19432,351,841 Seem June-20,i1944 FOREIGN PATENTS Number; Country Date408,909, GreatBritain ,Apr. 19; 1934:

